1. Field of the Invention
The present invention relates to a capacitive input device that detects a position of an operation body such as a finger or a hand located in front of an electrode group having a plurality of electrode portions.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2013-80290 discloses an invention of a touch sensor that enables so-called hover detection. The hover detection is also called hovering detection and refers to a detection operation of detecting presence of a finger or a hand in a position away from an operation surface of a touch sensor and a position thereof.
The touch sensor described in Japanese Unexamined Patent Application Publication No. 2013-80290 selects three lines of a plurality of lines arranged side by side, sets one line to a detection line, and sets the lines on both sides of the detection line to driving lines. In a detection operation, an approach state of a finger or the like is detected by obtaining a difference between capacitance between the detection line and the driving line located on one side and capacitance between the detection line and the driving line located on the other side. Further, a position on a coordinate of the approaching finger is detected by sequentially switching selection positions of the three lines.
The touch sensor described in Japanese Unexamined Patent Application Publication No. 2013-80290 performs an operation of sequentially switching combinations of the detection line and the driving lines, which include three lines, in a plurality of X lines and a plurality of Y lines.
In this configuration, when a hover detection distance that is a distance at which the finger or the hand can be detected from the operation surface is lengthened, capacitive coupling between a central detection line and the driving lines on both sides thereof should be larger in comparison with capacitance between the finger or the hand and the detection line, and an S/N ratio is easily degraded when approach of the finger or the hand is detected. Further, since an operation of sequentially switching the combination between the detection line and the driving line to all of the X lines and all the Y lines is performed, the number of times the lines are switched increases and a burden on a control circuit increases.